Abstract

Rapid Prototyping (RP) technology is actively studied to be implemented in Investment Casting (IC) process. Nowadays RP techniques were studied for the feasibility as IC master pattern, in terms of pattern collapsibility and drainage during burnout. The purpose of study is to determine the characteristic of Visijet® SR200 acrylate material during burnout process. Traditional IC patterns made from wax have properties that limit their application, in precision casting especially for parts with thin geometries that readily break or deform conventional when handled or dipped in the refractory slurry. Furthermore,it is not economical when producing small number of parts. Non wax pattern fabricated for IC process, revealed that ceramic shell cracking due to excessive thermal expansions, incomplete collapsibility of pattern during burnout, residual ash and poor surface finish. Thermogravimetric analysis (TGA) was used to measured the weight loss of acrylate material as the temperature was increased. TGA measured the change of material’s mass as it is heated. It represents the decomposition temperature after being subjected to varying temperatures, as well as the amount of residual ash. In this experiment, the temperature range was from 20ºC to 700ºC with 5ºC increment. Experiment results shows the values of material’s optimum reaction temperature and decomposing temperature of Visijet® SR200 acrylate. The percentages of remaining materials were also monitored throughout the process to obtain the amount of residual ash. All of the temperature value obtained is a resemblance for the actual burnout process and can be used as references.